The present invention relates to a brush holding device for holding brushes in contact with slip rings of an alternator for use in a vehicle.
Alternators are commonly used as electric power sources of vehicles such as automobiles and so forth. As will be described later in detail with reference to the drawings, the conventional alternators involved various problems. For instance, a pig tail electrically connecting the brush to a terminal plate tends to be caught and pinched between adjacent turns of the coiled spring, which surrounds the pig tail and presses the brush against the slip ring, due to vibration of the vehicle on which the alternator is mounted and often results in a cutting of the pig tail. The pig tail is usually stranded from element wires of copper. Therefore, as the pig tail is soldered at its one end to the terminal plate, the molten solder penetrates into the pig tail toward the brush due to wick or capillary action of the pig tail. The solidified solder deteriorates the flexibility of the pig tail which reduces to smoothness of the radial movement of the brush. In addition, in order to obtain a sufficiently high rigidity and stability of the mechanical and electrical connection between the brush and the pig tail, the effective length of the brush is inevitably shortened uneconomically.